refactor: remove legacy store.ts and crafting-slice.ts, complete modular store migration

- Delete store.ts (355 LOC monolithic store, zero imports)
- Delete crafting-slice.ts (379 LOC legacy crafting module)
- Inline createStartingEquipment() into craftingStore.ts
- Remove legacy equipment/inventory fields from GameState
- Remove EquipmentDef from game.ts imports (unused)
- Fix duplicate EquipmentSpellState export in types.ts
- Fix bluePrintId typo in craftingStore.ts
- Update stores/index.ts to import CraftingState/CraftingActions from craftingStore.types
- Update EquipmentTab.test.ts to test store state instead of deleted module
- Clean up stale comments referencing crafting-slice.ts
- Reduce TS errors from 83 to 72 by removing conflicting legacy types

docs/project-structure.txt

@@ -330,10 +330,8 @@ Mana-Loop/
 │       │   ├── crafting-equipment.ts
 │       │   ├── crafting-loot.ts
 │       │   ├── crafting-prep.ts
-│       │   ├── crafting-slice.ts
 │       │   ├── crafting-utils.ts
 │       │   ├── effects.ts
-│       │   ├── store.ts
 │       │   └── types.ts
 │       └── utils.ts
 ├── test-results/